Swim fin



FIG. 1 is a top plan view of a left foot swim fin showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a back elevational view thereof.

The ornamental design for a swim fin, as shown and described.